Aboard ships; in nuclear, petrochemical, and water treatment plants; in the treatment of wastewater effluents, and the like, it is often necessary that valves of varying sizes be continuously opened, closed, or controlled. Heretofore, such valves were manually operated, or opened or closed completely or partially from a remote control point. Many of such valves are oftentimes controlled by a handwheel which controls the opening and closing of the remotely disposed or inaccessible valves by means of rotatable flexible shafts communicating therebetween. Since the stems of these valves are provided in a variety of configurations, typically a tapered square of varying lengths and degree of taper, it was necessary that the flexible shaft assemblies be specifically fitted with adapters which would engage the particular valve stem being controlled. It was thus necessary to maintain an inventory of assorted adapters which added to the overall expense of plant operation, as well as requiring constant and time-consuming change-overs.
Further, in the marine valve industry, for example, in some cases it is the practice for sealing material to leak slightly from the valve gland nut to prevent excessive drying of the enclosed sealing material. The universal-type adapter of the present invention permits the gland nut to "leak" since the adapter does not contact the gland nut. The leaked sealing material however does not adversely affect the present shaft assembly since it is completely watertight. Turning the gland nut does not twist the casing of the flexible shaft assembly used in the present device as in prior art devices since the casing remains completely free of the gland nut. The present casing is free-positioning, or free to rotate as torsional stresses are produced therein, thus obviating any need for expensive braided casings, and permitting inexpensive plastic tubing, for example, to be used in lieu thereof. The present flexible shaft assembly is water tight, a desirable feature for applications envisaged for the device to be hereinafter claimed.
Briefly, the flexible shaft rotates the present adapter which engages the tapered valve stem. The adapter is provided with a pair of coincident tapered intersecting square bores of different size, disposed symmetrically, such that a line drawn through opposing corners of either square bore bisects opposing sides of the other; and each side of the larger square bore is intersected by a portion of the smaller, and vice versa. Thus, either of the two tapered square bores, depending upon the length and degrees of taper thereof, is capable of engaging tapered valve stems of many different sizes.